Open type magnetic resonance imaging system which allows for easy access to the patient being examined

ABSTRACT

A magnetic resonance imaging system includes a lower body which has a flat upper surface, and contains a first magnetic pole, an upper body which has a lower surface disposed in opposed relation to the upper surface of the lower body, and contains a second magnetic pole, a bed disposed adjacent to the lower body, and a pair of support posts which are provided respectively on right and left sides of the lower body, and interconnect the lower body and the upper body. A space, formed between the lower surface of the upper body and the upper surface of the lower body, is open at least toward the bed between the pair of right and left support posts.

BACKGROUND OF THE INVENTION

This invention relates generally to a magnetic resonance imaging system(hereinafter referred to as "MRI system"), and more particularly to aMRI system in which considerations, contributing to easy handling, aregiven to the subject to be examined (hereinafter referred to as"patient"), and also the efficiency of operations, such as a medicaltreatment to be given to the patient by a doctor, and an examinationoperation to be effected by a technician or the like (The doctor and thetechnician will hereinafter be referred to as "doctor or the like"), isimproved.

A MRI system utilizes nuclear magnetic resonance (NMR) phenomena toprovide an image of a cross-sectional area of that portion of thepatient to be examined for diagnostic purposes. In such a MRI system, inorder to produce NMR phenomena on the patient's portion to be examined,it is necessary to produce a strong magnetic field and then to locatethe patient's portion to be examined in this magnetic field.

In conventional MRI systems, generally, a bore such as a tunnel isformed in a strong magnetic field, and the patient is put into thisbore. In such a system, although the strong magnetic field can be easilyformed, the patient must be loaded into the narrow bore, which hasinvited a problem that the examination can not be carried out easily.Japanese Patent Unexamined Publication No. 62-26052 discloses a MRIsystem not using a tunnel space, in which one side of a measurementspace is open.

In the conventional MRI systems, the measurement space is formed in thetunnel, or is open at its one side with the remaining sides closed bywalls. Therefore, when the patient is inserted into the measurementspace for examination purposes, he tends to feel oppressed and uneasy,and it has often been difficult to properly examine a patient havingclaustrophobia. Moreover, the doctors or the like have now increasinglydesired to give a medical treatment to the patient simultaneously withthe examination operation; particulerly when the patient has anemergency condition, it is necessary to effect a medical treatmentsimultaneously with the examination. In such a case, the doctors or thelike need to gain access to the patient from opposite sides of thepatient. With conventional MRI systems, however, it has been impossibleto achieve this.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a magnetic resonanceimaging system capable of decreasing oppressed or uneasy feelings inpatients to be examined during examination. And, it is another object ofthe present invention to provide a magnetic resonance imaging system inwhich doctors or the like can easily effect an operation of theexamination or a medical treatment at the same time during theexamination.

In order to achieve such objects of the present invention, there isprovided a magnetic resonance imaging system including a lower bodywhich has a flat upper surface and contains a first magnetic pole, anupper body which has a flat lower surface disposed in opposed relationto the upper surface of the lower body and contains a second magneticpole, the lower body and the upper body forming an examination space,and a pair of support posts which are provided respectively on sides ofthe examination space, i.e. both side surfaces of the lower body. Thesesupport posts interconnecting the lower body and the upper body; theexamination space being open at least toward a bed between the pair ofsupport posts.

In order to achieve further the above objects according to the presentinvention, the support posts are located outside the lower body, and arefixed to the side surfaces of the lower body which extend toward a rearside thereof from a connecting portion of the lower body and the bed. Aspace is provided for permitting the effecting of a medical treatment atthe same time during the doctor's examination as needed at the sidesurfaces thereof between the support posts and the connecting portion ofthe lower body.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a MRI system in accordance with anembodiment of the present invention as seen at an angle from the frontside thereof;

FIG. 2 is a front-elevational view of the MRI system body;

FIG. 3 is a perspective view of the MRI system body as seen at an angleform the rear side thereof;

FIG. 4 is a side-elevational view of the MRI system, showing the doctoror the like effecting an examination operation while sitting on a chair;

FIG. 5 is a front-elevational view of the MRI system showing the doctoror the like effecting the examination operation at a lateral sidethereof;

FIG. 6 is a plan view of the MRI system showing the doctor or the likeeffecting the examination operation at the lateral side thereof;

FIG. 7 is a plan view showing the range of the examination operationeffected by the doctor or the like at the lateral side of the MRIsystem;

FIG. 8 is a plan view showing the range of the examination operationeffected by the doctor or the like at the rear side of the MRI system;

FIG. 9 is a perspective view of a MRI system in accordance with anotherembodiment of the present invention;

FIG. 10 is a perspective view of the MRI system of FIG. 9 as seen fromthe rear side thereof; and

FIG. 11 is a front-elevational view of an operating device used in theMRI system in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

One preferred embodiment of the present invention will now be describedwith reference to FIGS. 1 to 3.

FIG. 1 is a perspective view of a MRI system of the invention as seen atan angle from the front side thereof. A body of this MRI system includesa lower body 40 having a substantially circular upper surface, an upperbody 70 which is disposed above the lower body 40, and has asubstantially circular lower surface, a pair of opposed right and leftsupport posts 62 and 64 which interconnect the lower body 40 and theupper body 70 in such a manner that the lower body 40 and the upper body70 are disposed generally between the two support posts 62 and 64. At afront side of the MRI system body of FIG. 1, that is, at one side of thetwo support posts 62 and 64, a bed 10 is disposed adjacent to the lowerbody 40 through a connecting portion 42. In this MRI system, the patientis placed on the bed 10, and is transferred or loaded to the lower body40. In the lower body 40, an examination is effected using knownmagnetic resonance phenomena, and results of the examination aredisplayed as an image in a display portion of a central operating device(not shown).

The bed 10 includes a bed body 14, a top plate 12 mounted on the bedbody 14, and a bed leg 18. The top plate 12 is driven to move inlongitudinal and transverse directions of the bed 10 by a drive devicecontained in the bed 10. A pair of bed side portions 16, made of a softmaterial, such as foamed urethane, sponge or rubber, are provided atopposite lateral sides of the bed body 14, respectively, and these bedside portions 16 prevent the patient from injury while he moves onto thebed, and also absorb an impact force produced when a stretcher, on whichthe patient is placed, is brought into contact with the lateral side ofthe bed 10. After the patient is placed on the bed 10, the top plate 12is moved forward, backward, right and left, so that the patient can beaccurately loaded to the lower body 40. This operation can be carriedout by any one of a pair of operating devices 72 and 74 which aremounted respectively on right and left portions of a front side of anouter peripheral surface of the upper body 70 facing the bed 10, a rearoperating device 75 which is mounted on the rear side of the outerperipheral surface of the ceiling portion 70, and the central operatingdevice (See FIGS. 1 to 3). The leg 18 of the bed 10 is much smaller incross-sectional area than the bed body 14, and is disposed at a centralportion of the bed body 14, and the outer periphery of the leg 18 issufficiently recessed inwardly from the outer periphery of the bed body14, thus providing a sufficient space at the feet of the doctors or thelike that the they can move freely around the bed. This facilitates theexamination operation.

The upper surface of the lower body 40 is disposed in opposed relationto the lower surface of the upper body 70, and the lower body 40 and theupper body 70 contain respective opposed inclined magnetic field coils,irradiation coils, receiving coils and magnetic poles, and circularyokes 47 and 79 for these parts are also contained respectively in thelower body 40 and the upper body 70, as shown in FIG. 6. The lower body40 has the bed connecting portion 42 formed at a central portion of thefront side thereof for connection to the bed 10. A pair of outerperipheral surfaces (arcuate surfaces) 46 and 48 of the lower body 40,which lie between one end of the bed connecting portion 42 and the rightsupport post 62 and between the other end of the bed connecting portion42 and the left support post 64, respectively, are substantially part ofa cylindrical surface having its axis disposed on an axis 41 of thelower body 40. With this construction, the doctor or the like can movethe patient from either of the right and left outer peripheral surfaces46 and 48 according to the need, and also when the patient to beexamined requires the attendance of a nurse or a medical treatment, anecessary medical instrument, such as an oxygen mask and an instillator,can be applied to the patient from the right and left outer peripheralsurfaces 46 and 48. The lower body 40 has a circular shape, and thatsurface of the bed connecting portion 42 facing the bed 10 is straightso as to accurately connect the circular lower body 40 to the bed andalso to lessen the burden on the patient during transfer of the patientto the lower body 40.

An upper peripheral edge of the lower body 40 is chamfered or cut off toprovide a chamfered or beveled portion 52. The chamfered portion 52 ismade of a soft material. With this construction, the doctors or the likeand the patient are prevented from being injured by the upper edge ofthe lower body 40, and also the doctors or the like can easily approachthe patient. A lower peripheral edge portion of the lower body 40 isrecessed as at 54, thus providing a space at the feet of the doctors orthe like so that they can easily move around the lower body 40 duringthe examination and a medical treatment.

The front side (surface) and opposite lateral sides (surfaces) of theupper body 70 continuous therewith are defined by a substantiallysemi-circular surface, and therefore the degree of opening of anmeasurement space is high, so that the patient feels less oppressed. Inaddition, because of this widely-open arrangement, the doctors or thelike can effect the operation easily. A lower peripheral edge of theupper body 70 is chamfered or cut off to provide a chamfered or beveledportion 82, and this chamfered portion 82 is made of a soft material.With this construction, even if the doctors or the like hit their headagainst this edge during the operation, they will not be injured.

The lower body 40 and the upper body 70 are interconnected by the pairof right and left support posts 62 and 64 provided respectively onopposite (right and left) sides of the lower body 40 and the upper body70 as seen from the bed 10 (FIG. 1) in such a manner that the lower body40 and the upper body 70 are interposed between the two support posts 62and 64. A magnetic circuit is formed in these support posts 62 and 64,and is connected to the magnetic poles provided respectively within thelower body 40 and the upper body 70. A circular yoke 67 is contained ineach of the two support posts 62 and 64, as shown in FIG. 6. The rightand left support posts 62 and 64 are spaced apart from the lower body40, so that a space is formed between the outer periphery of the lowerbody 40 and the outer periphery of each of the two support posts 62 and64. As a result, a space 66 is formed between the inner side of theright support post 62 and the outer periphery of the measurement spaceformed between the lower body 40 and the upper body 70 whereas a space68 is formed between the inner side of the left support post 64 and theouter periphery of the measurement space. The support posts 62 and 64are formed into a generally square cross-section, so that extensionportions, which constitute side tables 76 and 78, respectively, areformed respectively at the bottoms of these spaces 66 and 68. With thisconstruction, the patient placed on the lower body 40 can feel easy, andalso when applying a medical treatment to the patient, medicalinstruments can put on the side tables 76 and 78, and the doctors or thelike can effect the operation easily. Illumination means 61 and 63 canbe provided respectively on the inner sides of the right and leftsupport posts 62 and 64 respectively facing the spaces 66 and 68, or onthe side tables 76 and 78, respectively. In this case, the space is madebrighter, so that the patient can feel less oppressed, and also thedoctors or the like can effect the operation more easily, which preventserrors in the operation. The right operating device 72 is provided inthe outer peripheral surface of the upper body 70, and is disposedbetween the front side thereof which faces the bed 10 and the rightsupport post 62, whereas the left operating device 74 is provided in theouter peripheral surface of the upper body 70, and is disposed betweenthe front side thereof and the left support post 64. Further, the rearoperating device 75 is provided in the rear surface of the upper body 70lying between the two support posts 62 and 64, as shown in FIG. 3. Withthis arrangement, the doctor or the like, even if positioned at any ofthe right, left and rear sides of the lower body 40, can effect theoperations such as the movement of the bed 10 and the start andinterruption of the examination operation.

The space, formed by the lower body 40 and the upper body 70, is alsowide open at the rear side as shown in FIG. 3. This open construction isobtained by recessing the rear sides of the lower body 40 and the upperbody 70 over a wide range between the two support posts 62 and 64. Morespecifically, a recess 71 is formed in the rear side of the outerperiphery of the lower body 40, and a recess 73 is formed in the rearside of the outer periphery of the upper body 70. With thisconstruction, the distance from the rear side to the center of the lowerbody 40 is reduced, so that the operation can be effected easily in themeasurement space.

In the above embodiment, as shown in FIG. 6, the support posts have thesurfaces not opposed to the lower body as formed as large curvedsurfaces. Although it is described above that the support posts have agenerally square crosssection, all the side surfaces thoseof may be madestraight, the crosssections may be square, and all corner portions ofthe support posts may be cut off.

A central light marker 92 is mounted on the front side of the cutportion 82 provided in the outer peripheral surface of the upper body 70adjacent to its lower surface, and a pair of side light markers 94 and96 are provided on the side surfaces of the right and left support postsat the sides of the examination space 62 and 64, respectively. Theselight markers 92, 94 and 96 emit light beams serving as a reference ofthe positional relation.

FIG. 4 is a view showing the doctor or the like conducting theexamination while sitting on a chair. A height L1 of the upper surfaceof the lower body 40 is in the range of between 600 mm and 800 mm sothat the doctor or the like can put his head into the measurement spaceformed between the upper surface of the lower body 40 and the lowersurface of the upper body 70. A height L3 of the lower surface of theupper body 70 from a floor surface on which the lower body 40 is mountedis set to 1,285 mm in this embodiment. Preferably, this height L3 is inthe range of between 1,000 mm and 1,550 mm. In order to enhance theresolution of the image obtained as the examination result, it isdesirable that the distance or spacing between the upper surface of thelower body 40 and the lower surface of the upper body 70 be small, andfor this reason the height L3 is set to 1,285 mm. A vertical dimensionL2 of the measurement space between the upper surface of the lower body40 and the lower surface of the upper body 70 is in the range of between350 mm to 435 mm. With this value, the patient, lying down on the lowerbody 40, can move both hands, and if this dimension is increased, thepatient can move his hands more easily, but the precision of theexamination is lowered.

The lower body 40 has the chambered portion 52 formed at the upperperipheral edge thereof, and the upper body 70 has the chamfered portion82 formed at the lower peripheral edge thereof. Therefore, the doctorsand other attending personnel are prevented from being injured uponstriking against these edges. The recess 54 is formed at the lowerperipheral edge portion of the lower body 40, and therefore the nails ofthe foot of the doctor or the like will not strike against this lowerend. FIG. 5 is a view showing the doctor or the like effecting theoperation while standing up at the lateral side of the lower body 40.Since the lower peripheral edge of the upper body 70 is cut off orchamfered, the doctor or the like can better look into the measurementspace above the lower body 40, so that the operation can be carried outeasily. The lower peripheral edge of the upper body 70 may be chamferedover the entire periphery thereof to provide the chamfered portion 82either in such a manner that the outer peripheral surface thereof isstraight in transverse cross-section as indicated at the left of FIG. 5,or in such a manner that the outer peripheral surface is rounded intransverse cross-section as indicated by a broken line at the right. InFIG. 5, preferably, an inclination angle 300 is in the range of between40° and 75°. In the case where the chambered portion 82 has the roundedperipheral surface, the radius of curvature thereof is preferably in therange of between 50 mm and 80 mm. As shown in FIGS. 1 and 3, the uppersurface of the upper body 70 is flat at its outer peripheral portion,and the remainder surrounded by this outer peripheral portion isslightly outwardly convex to assume a dome-like configuration, therebyincreasing the strength.

FIG. 6 is a view showing the doctor or the like standing up at thelateral side of the lower body 40. The center or axis 41 of the lowerbody 40 coincides with the center of the measurement space, and it ispreferred that portion of the patient to be examined should be disposedon this center 41. In this condition, the doctors or the like can bepositioned accurately at the opposite sides of the lower body 40, andhence at the opposite sides of the patient, respectively, and thereforethe various operations can be carried out efficiently. The light markers92, 94 and 96 accurately indicate a reference position 141 of the bedand the reference position 41 of the measurement space by light beamsemitted therefrom. The patient is properly positioned by the referenceposition 141 of the bed 10, and then is automatically moved ortransferred into the reference position in the measurement space. Atthis time, however, if the patient moves himself, a deviation resultsfrom this movement. In this case, the doctors or the like must againposition the patient with respect to the reference position in themeasurement space; however, since the light markers 92, 94 and 96 canindicate the position of the center of the measurement space, theposition of the patient can be easily corrected accurately.

FIG. 7 is a view showing an area of the operation to be effected by thedoctor or the like standing up at the lateral side of the lower body 40.If the height of the lower body 40 is 1,000 mm, the doctor or the likecan effect the operation in the range of an operation line 202, that is,in the range of 600 mm from the doctor or the like. If the height of thelower body 40 is about 800 mm, the operation range is increased to therange of an operation line 204, that is, in the range of 1,000 mm fromthe doctor or the like. In this embodiment, the height of the lower body40 is in the range of between 600 mm and 750 mm, the operation range isincreased. In the above embodiment, the hands can reach deeper beyondthe center of the lower body 40, so that the various operations can bedealt with.

FIG. 8 is a view showing the doctor or the like effecting the operationwhile standing up at the rear side of the lower body 40. If the heightof the lower body 40 is 1,000 mm, the operation range is in the range ofan operation line 206, that is, in the range of 600 mm from the doctoror the like, as described above for FIG. 7. If the height of the lowerbody 40 is about 800 mm, the operation range is increased to the rangeof an operation line 208, that is, in the range of 1,000 mm from thedoctor or the like. In this embodiment, the height of the lower body 40is in the range of between 600 mm and 750 mm as explained for FIG. 7,the operation can be effected in the range of the operation line 208,that is, in the range of 1,000 mm from the doctor or the like. Since therear side is concave inwardly as shown in FIG. 8, the operation range isfurther increased.

Furthermore, the above L1 is desirable to be made the value between 600mm and 750 mm in case of the patient to be examined lying on the lowerbody for examination and further desirable to be the value between 600mm and 800 mm in case of the doctor or the like operating while sittingon a chair or standing up.

And, the above L2 is desirable to be made the value between 400 mm and435 mm as a dimension thereof for not reducing an accuracy of theexamination and in such a manner that the patient to be examined can liewith a space on the lower body. Since the accuracy of the examinationcan be improved by setting the height dimension thereof lower value, theL2 is further desirable to be made the value between 350 mm and 435 mm.

Furthermore, the above L3 is most desirable to be made the value between950 mm and 1235 mm when the most suitable values of the above L1 and L2are taken into consideration.

FIGS. 9 and 10 show a MRI system according to another embodiment of thepresent invention. A front portion of a lower body 40 is connected to abed 10 in continuous relation thereto. A pair of opposed right and leftsupport posts 62 and 64 are provided at the rear side of the lower body40 facing away from the bed 10, and the lower body 40 and an upper body70 are interconnected by the right and left support posts 62 and 64. Thelower body 40 and the upper body 70 contain respective opposed magneticpoles, inclined magnetic field coils, irradiation coils, receiving coilsand yokes, as described above in the preceding embodiment. Thesemagnetic poles are electromagnetically connected together through amagnetic circuit formed in the right and left support posts 62 and 64.Opposite lateral sides of the lower body 40 are open, so that thedoctors or the like can make an examination of the patient, and canapply a necessary medical treatment to the patient in a manner asdescribed above in the preceding embodiment. The distance between eachof the opposite sides of the lower body 40 and the center thereof is 750mm. Preferably, this distance is in the range of between 500 mm and 750mm. With this range, the hands can reach the patient from the right,left, front and rear sides, so that the medical treatment can be carriedout easily. The bed 10 has a top plate so as to easily move or transferthe patient into the lower body 40 as in the preceding embodiment.

The rear side of this system is also open, and the doctors or the likecan effect the necessary operation and treatment. In order to make therear side wide open, the distance between the right and left supportposts 62 and 64, that is, between the outer peripheries of the twosupport posts, is set to 1,010 mm. A front portion of the upper body 70is reduced in thickness. This is done not only to reduce the weight ofthe upper body 70 but also to reduce the thickness of the front portionof the magnetic pole so as to make a magnetic distribution of themagnetic pole generally uniform.

FIG. 11 shows details of an operating portion. Positional deviations,that is, deviations in the directions of the width and the height, ofthe bed from the lower body are numerically displayed on a LED displayportion 110. Operation keys 102 are used for operating the bed, and the"LEFT" key and "RIGHT" key are used for moving the bed right and left,and when these keys are operated, indication elements 127 and 129 arelighted to indicate the direction of movement of the bed. When thecenter of the lower body coincides with the centerline of the bed, anindication element 128 is lighted.

When the "UP" key or the "DOWN" key among the operation keys 102 isoperated, the position of a bed 125 in the LED display with respect to alower body 124 in the LED display in the direction of the height isindicated by indication elements 131 and 130. The indication element 130is lighted when the height of the bed is generally equal to the heightof the lower body, whereas the indication element 131 is lighted whenthe bed is at a height lower than the lower body, or the bed is in adownward movement mode.

A key 103 is used for indicating emergency stop of the examinationoperation. Keys 104 are used for turning on an off the light markers andfor releasing the setting of indication of the reference position. A key105 is used for turning on an off the illumination devices. Keys 106 areused for controlling the bed so as to move the patient into and out ofthe lower body. A key 107 is an automatic control key for loading andunloading the patient. Keys 108 are operation keys for indicating thecompletion of the preparation for the magnetic resonance operation andfor starting the magnetic resonance operation. The above keys arearranged in a predetermined order, and more specifically the operationkeys 104 related to the positioning of the patient, as well as theillumination control key 105, are disposed at an upper portion of theoperating portion, and the bed operating keys 102, 106 and 107 aredisposed next to these keys, and the magnetic resonance operation andscan keys 108 are disposed next to these keys. With respect to thecontrol of the position of the bed, the position of the bed with respectto the lower body is numerically displayed in a display 120 at the leftside portion, and the contents of the operation are graphicallyindicated by the indication elements 127, 129 and 131. Therefore, thecontents of the operation can be confirmed, thus preventing an erroneousoperation.

In the above embodiments, although the right and left support posts 62and 64 are offset rearwardly with respect to the center of the lowerbody 40, these support posts 62 and 64 may be offset forwardly towardthe bed. In this case, when a tebet 11 is brought to the lower body, thesense of oppression may slightly increase. However, once it isintroduced into the measurement space, the degree of opening of thepatient's view is increased, and therefore the patient feels lessoppressed during the examination. When the patient requires a medicaltreatment in addition to the examination, necessary instruments can bebrought close to the lower body from the opposite sides and the rearside, since the rear side is wide open during the examination.Therefore, the operation can be carried out easily, and the efficiencyof the operation is enhanced.

With the above construction, the doctors or the like can be positionedat the opposite (right and left) sides of the lower body, and theexamination can be effected efficiently, and besides the doctors or thelike can respond to the patient, and also can apply a necessary medicaltreatment to the patient, using a medical instrument.

What is claimed is:
 1. A magnetic resonance imaging system forgenerating an image of a patient, comprising:a lower body having a flatupper surface, said lower body having a first magnetic pole providedtherein, said lower body rests on a floor surface, said patient rests onsaid lower body; an upper body having a lower surface disposed inopposed relation to said upper surface of said lower body, said upperbody having a second magnetic pole provided therein; and a pair ofsupport posts provided outside said lower body and connected to saidlower body, said pair of support posts support said upper body, whereinsaid upper body have at least a front portion of a lower peripheral edgethereof as being chamfered, wherein said upper body being positionedrelative to said lower body in a manner such that access to said patientresting on said lower body is not obstructed by said upper body, whereinsaid first and second magnetic poles produce a magnetic field which isused to generate said image, wherein said lower body is provided with anouter peripheral surface, and a bed connecting portion formed to projectbefore said outer peripheral surface, wherein said upper body have atleast a front side formed in a circular arc shape, an outer peripheralsurface formed vertically to said lower surface and concentric with acircular arc of said lower surface to have a diameter larger than thatof said circular arc, and said front portion being formed as an obliquesurface between said lower surface and said outer peripheral surface,wherein a space is formed between said lower body and said upper body,wherein said pair of support posts is connected to each side surface ofsaid lower and upper bodies and disposed symmetrically in right and leftdirections with respect to said lower and upper bodies, and wherein saidpair of support posts have a recess formed at said space side of each ofsaid pair of support posts in an area of said space, and each frontsurface of said pair of support posts formed substantially vertical tosaid side surface, each front surface of said pair of support postsbeing connected to said outer peripheral surface of said lower body, andsaid front surface of said lower body projecting at a connectingposition thereof.
 2. A magnetic resonance imaging system for generatingan image of a patient, comprising:a lower body having a flat uppersurface, said lower body having a first magnetic pole provided therein,said lower body rests on a floor surface, said patient rests on saidlower body; an upper body having a lower surface disposed in opposedrelation to said upper surface of said lower body, said upper bodyhaving a second magnetic pole provided therein; and a pair of supportposts provided outside said lower body and connected to said lower body,said pair of support posts support said upper body, wherein said upperbody have at least a front portion of a lower peripheral edge thereof asbeing chamfered, wherein said upper body being positioned relative tosaid lower body in a manner such that access to said patient resting onsaid lower body is not obstructed by said upper body, wherein said firstand second magnetic poles produce a magnetic field which is used togenerate said image, wherein said lower body is provided with an outerperipheral surface, and a bed connecting portion formed to projectbefore said outer peripheral surface, wherein said upper body have atleast a front side formed in a circular arc shape, an outer peripheralsurface formed vertically to said lower surface and concentric with acircular arc of said lower surface to have a diameter larger than thatof said circular arc, and said front portion being formed as an obliquesurface between said lower surface and said outer peripheral surface,wherein a space is formed between said lower body and said upper body,wherein said pair of support posts is disposed outside said lower andupper bodies and disposed symmetrically in right and left directionswith respect to said lower and upper bodies, said pair of support postshaving front surfaces connected to each other at said side surfaces ofsaid lower and upper bodies so as to project front portions of saidlower and upper bodies, and wherein said pair of support posts have afront surface and side surfaces, respectively, said front surfaces ofeach of said pair of support posts being connected to said projectingside surfaces of said lower body, and said side surfaces of said lowerbody being located inside with respect to said side surfaces of each ofsaid pair of support posts.
 3. A magnetic resonance imaging system forgenerating an image of a patient, comprising:a lower body having a flatupper surface, said lower body having a first magnetic pole providedtherein, said lower body rests on a floor surface, said patient rests onsaid lower body; an upper body having a lower surface disposed inopposed relation to said upper surface of said lower body, said upperbody having a second magnetic pole provided therein; and a pair ofsupport posts provided outside said lower body and connected to saidlower body, said pair of support posts support said upper body, whereinsaid upper body have at least a front portion of a lower peripheral edgethereof as being chamfered, wherein said upper body being positionedrelative to said lower body in a manner such that access to said patientresting on said lower body is not obstructed by said upper body, whereinsaid first and second magnetic poles produce a magnetic field which isused to generate said image, wherein said pair of support posts have amagnetic circuit for connecting said first magnetic pole with saidsecond magnetic pole, said support posts being connected to sideportions of said lower and upper bodies and disposed symmetrically inright and left directions of those bodies, wherein said lower body isprovided with a projection portion provided by projecting a frontportion of said lower body before said pair of support posts, a bedconnecting portion formed at a tip end of said projection portion, andside surfaces vertical to said flat upper surface and formed at saidprojection portion, wherein said upper body has at least a front sidebefore said pair of support posts and formed in a circular arc shape, anouter peripheral surface at least vertical to said lower surface, havinga diameter larger than that of said circular arc of said lower surface,further provided before said connecting portion thereof to said pair ofsupport posts above said lower surface, and said front portion beingformed as an oblique surface obliquely inwardly between said outerperipheral surface and said circular arc of said lower surface, whereina first space is provided between said flat upper surface and said lowersurface, said first space being defined directly below said lowersurface, wherein said pair of support posts have a first space sideportion of a front surface of each of said support posts correspondingto a height of said first space, said first space side portion beingformed to locate backward with respect to the front surface of each ofsaid support posts in a portion connected to the outer peripheralsurface of said upper body, and wherein said projection portion of saidlower body has an outer appearance provided with said projection portionof said lower body projecting from a connecting position of said frontsurface of each said pair of support posts with said side surface ofsaid lower body.
 4. A magnetic resonance imaging system for generatingan image of a patient, comprising:a lower body having a flat uppersurface, said lower body having a first magnetic pole provided therein,said lower body rests on a floor surface, said patient rests on saidlower body; an upper body having a lower surface disposed in opposedrelation to said upper surface of said lower body, said upper bodyhaving a second magnetic pole provided therein; and a pair of supportposts provided outside said lower body and connected to said lower body,said pair of support posts support said upper body, wherein said upperbody have at least a front portion of a lower peripheral edge thereof asbeing chamfered, wherein said upper body being positioned relative tosaid lower body in a manner such that access to said patient resting onsaid lower body is not obstructed by said upper body, wherein said firstand second magnetic poles produce a magnetic field which is used togenerate said image, wherein said pair of support posts have a magneticcircuit for connecting said first magnetic pole with said secondmagnetic pole, said support posts being connected to side portions ofsaid lower and upper bodies and disposed symmetrically in a right andleft direction of those bodies, wherein said lower body is provided witha projection portion provided by projecting a front portion of saidlower body before said pair of support posts, a bed connecting portionformed at a tip end of said projection portion, and side surfacesvertical to said flat upper surface and formed at said projectionportion, wherein said upper body has at least a front side before saidpair of support posts and formed in a circular arc shape, an outerperipheral surface at least vertical to said lower surface, having adiameter larger than that of said circular arc of said lower surface,further provided before said connecting portion thereof to said pair ofsupport posts above said lower surface, and said front portion beingformed as an oblique surface obliquely inwardly between said outerperipheral surface and said circular arc side of said lower surface,wherein a first space is provided between said flat upper surface andsaid lower surface, wherein each of said pair of support posts areprovided with a sectional area of a portion located slightly above saidflat upper surface being smaller than that of a portion located slightlybelow said flat upper surface, thereby allowing said first space to beformed to spread toward said pair of support posts, and further eachfront surface of said pair of support posts formed approximatelyperpendicular to the side surfaces of said pair of support posts, andwherein said pair of support posts each have a front surface connectedto the side surfaces of said projection portion of said lower bodyprojecting from said connecting portion.
 5. A magnetic resonance imagingsystem for generating an image of a patient, comprising:a lower bodyhaving a flat upper surface, said lower body having a first magneticpole provided therein, said lower body rests on a floor surface, saidpatient rests on said lower body; an upper body having a lower surfacedisposed in opposed relation to said upper surface of said lower body,said upper body having a second magnetic pole provided therein; and apair of support posts provided outside said lower body and connected tosaid lower body, said pair of support posts support said upper body,wherein said upper body have at least a front portion of a lowerperipheral edge thereof as being chamfered, wherein said upper bodybeing positioned relative to said lower body in a manner such thataccess to said patient resting on said lower body is not obstructed bysaid upper body, wherein said first and second magnetic poles produce amagnetic field which is used to generate said image, wherein said pairof support posts have a magnetic circuit for connecting said firstmagnetic pole with said second magnetic pole, said pair of support postsbeing connected to side portions of said lower and upper bodies anddisposed symmetrically at those bodies, wherein said lower body isprovided with a projection portion provided by projecting a frontportion of said lower body before said pair of support posts, a bedconnecting portion formed at a tip end of said projection portion, andside surfaces vertical to said flat upper surface and formed at saidprojection portion, wherein said upper body has at least a front sidebefore said pair of support posts and formed in a circular arc shape, anouter peripheral surface at least vertical to said lower surface, havinga diameter larger than said circular arc side of said lower surface,further provided before said connecting portion thereof to said pair ofsupport posts above said lower surface, and said front portion beingformed as an oblique surface obliquely inwardly between said outerperipheral surface and said circular arc of said lower surface, andwherein said pair of support posts have a recess formed at said firstspace side of each of said pair of support posts corresponding to aheight of said first space, each front surface of said pair of supportposts formed substantially vertical to said side surface thereof, saideach surface of said pair of support posts being connected to sidesurfaces of said projection portion of said lower body, and saidprojection portion of said lower body being projected at the connectingposition thereof.
 6. A magnetic resonance imaging system for generatingan image of a patient, comprising:a lower body having a flat uppersurface, said lower body having a first magnetic pole provided therein,said lower body rests on a floor surface, said patient rests on saidlower body; an upper body having a lower surface disposed in opposedrelation to said upper surface of said lower body, said upper bodyhaving a second magnetic pole provided therein; and a pair of supportposts provided outside said lower body and connected to said lower body,said pair of support posts support said upper body, wherein said upperbody have at least a front portion of a lower peripheral edge thereof asbeing chamfered, wherein said upper body being positioned relative tosaid lower body in a manner such that access to said patient resting onsaid lower body is not obstructed by said upper body, and wherein saidfirst and second magnetic poles produce a magnetic field which is usedto generate said image, wherein said pair of support posts have amagnetic circuit for connecting said first magnetic pole with saidsecond magnetic pole, said pair of support posts being connected to sideportions of said lower and upper bodies and disposed symmetrically in aright and left direction of those bodies, wherein said lower body isprovided with a projection portion provided by projecting a frontportion of said lower body before said pair of support posts, a bedconnecting portion formed at a tip end of said projection portion, andside surfaces vertical to said flat upper surface and formed at saidprojection portion, wherein said upper body has at least a front sidebefore said pair of support posts and formed in a circular arc shape, anouter peripheral surface at least vertical to said lower surface, havinga diameter larger than that of said circular arc of said lower surface,further provided before said connecting portion thereof to said pair ofsupport posts above said lower surface, and said front portion beingformed as an oblique surface obliquely inwardly between said outerperipheral surface and said circular arc of said lower surface, whereina first space is provided between said flat upper surface and said lowersurface, said first space being defined directly below said lowersurface, and wherein said pair of support posts are provided with arecess formed at a first space side of each said pair of support postscorresponding to a height of said first space, front surfaces connectedsubstantially vertical to the side surfaces of said lower body and saidprojection portion said lower body projecting at the connecting portionthereof.